add test

Signed-off-by: David Wertenteil <dwertent@armosec.io>

core/cautils/getter/utils_test.go

@@ -1,6 +1,7 @@
 package getter
 
 import (
+	"io"
 	"testing"
 
 	"github.com/stretchr/testify/require"
@@ -43,3 +44,56 @@ func TestIsNativeFramework(t *testing.T) {
 	require.Truef(t, isNativeFramework("nSa"), "expected nsa to be native (case insensitive)")
 	require.Falsef(t, isNativeFramework("foo"), "expected framework to be custom")
 }
+
+func Test_readString(t *testing.T) {
+	type args struct {
+		rdr      io.Reader
+		sizeHint int64
+	}
+	tests := []struct {
+		name    string
+		args    args
+		want    string
+		wantErr bool
+	}{
+		{
+			name: "should return empty string if sizeHint is negative",
+			args: args{
+				rdr:      nil,
+				sizeHint: -1,
+			},
+			want:    "",
+			wantErr: false,
+		},
+		{
+			name: "should return empty string if sizeHint is zero",
+			args: args{
+				rdr:      &io.LimitedReader{},
+				sizeHint: 0,
+			},
+			want:    "",
+			wantErr: false,
+		},
+		{
+			name: "should return empty string if sizeHint is positive",
+			args: args{
+				rdr:      &io.LimitedReader{},
+				sizeHint: 1,
+			},
+			want:    "",
+			wantErr: false,
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			got, err := readString(tt.args.rdr, tt.args.sizeHint)
+			if (err != nil) != tt.wantErr {
+				t.Errorf("readString() error = %v, wantErr %v", err, tt.wantErr)
+				return
+			}
+			if got != tt.want {
+				t.Errorf("readString() = %v, want %v", got, tt.want)
+			}
+		})
+	}
+}